Leukotriene B4 generation by blood polymorphonuclear leukocytes after incubation in urine

To investigate the capacity of leukocytes in urine to produce leukotriene B4 (LTB4), we evaluated calcium ionophore A23187-induced LTB4 generation by human blood polymorphonuclear leukocytes (PMNL) after these cells were incubated in urine under various conditions. LTB4 production was markedly reduced after incubation of PMNL in urine of high or low pH and high osmolarity. The production was also inhibited by a prolonged incubation period. There was a significant correlation (r = 0.82, p < 0.01) between LTB4 production and PMNL viability. Our results indicate that it is possible to evaluate the LTB4 production capacity of urinary PMNL by determining PMNL viability only. Furthermore acidification of urine hamper the LTB4 generation which might be unfavorable in vivo.